1. Field of the Invention
The present invention relates to a method for forming optimal characteristic curves of a solar cell and the system thereof in an automatic manner.
2. Description of the Related Art
With the gradual exhaustion of oil reserves and other non-renewable energy resources and more concern toward environmental protection, the development of alternative energy resources draws more and more attention from many governments. Among the alternatives for future energy sources, the development of solar cells is one of the most attractive solutions. Many countries are applying extensive effort toward developing this technology so as to reduce their heavy reliance on oil or other non-renewable resources.
Using a solar cell to transform solar energy into electricity is the primary basis of collecting solar energy. The principle activity of a solar cell is to use semiconductor photoelectrical transformation to generate electrical power. The transformation efficiency will directly affect the output power and, therefore, the selling price of the solar cell. Generally, solar cells are classified into different classes based on their efficiency testing. It is expected that higher transformation efficiency in a solar cell corresponds to a higher price. Therefore, an accurate, objective and rapid measuring method or system is an important tool for solar cell manufacturers.
U.S. Pat. No. 4,528,503 discloses a method and apparatus for measuring current and voltage of a solar cell. This method measures characteristic curves of the solar cells while in the states of open and closed circuits, respectively, and the voltage and current of the maximal output power are deduced from the measured data.
Other methods of determining the maximal output power utilize mostly human operations to read operation data and then manually select a linear or fixed square root equation to find voltage and current curves. However, such method is so subjective that the analysis result is not reliable.